In the past, stationary, vehicular and portable ceramic composite electrolytic devices such as fuel cells for generating electric power and heat or for generating oxygen, have been difficult to manufacture for numerous reasons. First, numerous prior art devices used ceramic-to-ceramic type fabrication techniques which resulted in a product which was not sufficiently tough to be reliable during transport or usage. The ceramic-to-ceramic interface was brittle and would tend to crack readily. Additionally, fabrication costs for such units were high due to the use of expensive ceramic materials, together with complicated manufacturing methods. The high temperature at which such devices must operate limited the choice of materials for use in the devices. Where metals were used, high operating temperatures tended to weaken the metals as well as increase their corrosion and oxidation rates. As a result, expensive ceramic materials were used. Such materials have had difficulties including cracking and failure of the seals. These difficulties are made worse in the event of shock, vibration and thermal cycling to high operating temperatures. Fabrication techniques may also have included expensive permanent or hermetic gas seals, which were often unsuccessful. Prior art units also tend to be too large to meet desired space and weight requirements. Moreover, such devices were unable to meet desired power requirements despite such additional disadvantages. For example, in the case of a stack of small cells having continuous output requirements for use in a micro-vehicle, minimal output such as a few Watts are desired. In a larger vehicle, manned or unmanned, power outputs are generally desired to be in the range of 1-100 kWatts. For large vehicles or stationary power supplies, for example for utility power, megawatt requirements may be desired. Devices of this type would preferably have relatively small physical dimensions.
Additional disadvantages with prior art techniques are set forth in the background of U.S. Pat. No. 5,069,987 concerning electrical power generation, which is incorporated herein by reference. Still further enhancements continue to be made to the mechanical properties of ceramic cell technology as discussed in U.S. Pat. No. 5,624,542. However, such improvements continue to have disadvantages, including the use of large amounts of expensive precious metals such as silver and palladium. Also, the use of increased amounts of metal in the composite result in undesirable direct electrical connections, which limit the usefulness of the cell in certain applications.